Antique brooch with a man portrait

Antique brooch with a man portrait. A nostalgic vintage costume jewelry piece. Age unknown Size approx.: 2.6 cm I am unsure what type of metal it is. There is some crazing on the glass. There is also signs of green oxidation which looks copper. This product is an older item with patina/abrasion, scratches or similar traces of the past. Tags: portrait brooch, vintage pin, photo pin, gift from boyfriend, girlfriend, Victorian